pr-check-block-via-labels.yaml

name: Block mergings PRs if it contains a blocking label (do-not-merge, hold)

on:
  pull_request:
    types:
      - labeled
      - unlabeled
      - synchronize
      - opened
      - reopened

permissions:
  contents: read
  pull-requests: read
  checks: write

jobs:
  fail-for-labels:
    runs-on: ubuntu-latest
    steps:
      - name: Block if PR has specific labels
        uses: actions/github-script@v7
        with:
          script: |
            const pullNumber = context.payload.pull_request.number;
            const { data: pullRequest } = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: pullNumber,
            });

            const blockingKeywords = ["do-not-merge", "hold"];

            pullRequest.labels.forEach(label =>
              blockingKeywords.forEach(blockingKeyword => {
                if(label.name.includes(blockingKeyword)) {
                  console.log(`Blocking merge due to blocking label "${blockingKeyword}"`);
                  throw new Error('Merging is blocked because this PR contains a blocking label.');
                }
              })
            )

            console.log(`No blocking labels found for PR ${pullNumber}`);